The SI (System Internationale) unit for luminous flux is the lumen. The lumen (Lm) is therefore a measure of the total amount of light (luminous flux) emitted per second by a light source and can therefore be used to compare the performance of different light sources and forms the basis for lighting calculations.

Colour Rendering Index

Recent spectral measurements for the MONOFLEX range of PCBs can be found below. This shows the exact correlated colour temperature (CCT) of each light source measured and the corresponding Colour Rendering Index (Ra). The results show the standard 2700K Samsung (S30 & S60) LED to have an impressive 87 Ra. Yet more impressive data from the Samsung LM561B LED!